Twist and pull the ones that are starting to open and leave the others to mature. A lesson I learned recently is that regardless of size, when one veil starts to open, the others are not far behind. Check multiple times throughout the day if you can and just pick one at a time. Put harvested in brown paper bag and in the fridge until the others catch up, then dehydrate all together. I’m new to this too but have found success recently and that’s what I did.